In a wire discharge machining apparatus, there has been proposed a technology for accurately grasping the remaining quantity of a wire in a wire bobbin and the consumption of the wire by discharge machining. By grasping the remaining quantity and the consumption of the wire, an operator can replace the wire bobbin before machining is suspended because of the insufficiency of the wire.
For example, Patent Literatures 1 and 2 propose technologies for calculating the remaining quantity of the wire from the weight of the wire bobbin and calculating a predicted machining length for a workpiece. Data obtained by the calculation is used in a replacement command for the wire bobbin and displayed on a display.
Patent Literature 3 proposes a technology for comparing the remaining quantity of a wire calculated from the rotating speed of a wire bobbin and the wire consumption of the entire program calculated from the wire consumption for each of the machining conditions and specifying a part where the wire runs out in a machining path.
Patent Literature 4 proposes a technology of a wire remaining quantity display apparatus for converting the measurement result of the wire weight into the wire length and displaying the obtained result. Patent Literature 5 proposes a technology for comparing the cumulative value of the wire consumption for each of the machining levels of the machining shapes and the remaining quantity of a wire and determining the available machining level.